Intumescing, water resistant fire retardant compositions comprising at least one water-insoluble metal metaphosphate, a polypentaerythritol, and a water insoluble aminoplast resin



United States Patent INTUMESCWG, WATER RESETANT FEZE RE- TARDANTCOMPQSITIONS CGMPRESING AT LEAST ONE WATER-INSOLUBLE METAL META-PHOSPHATE, A POLYPENTAERYTHRHTOL, AND A WATER INSOLUBLE AMINOPLAST RESINJulio H. Basto, New York, N.Y., and Murray M. Capp, Whippany, Cyril R.Davison, Princeton, and George H. Garbaden, East Orange, N.J., assignorsto Beniamm Moore & (30., New York, N.Y., a corporation of New Jersey N0Drawing. Filed July 21, 1959, Ser. No. 828,441 11 Claims. (Cl. 26022)The present invention relates to fire-retardant compositions, and ismore particularly directed to potentially intumescing and intumescingfire-retardant compositions for the coating of combustible orheat-deformable substrates to protect such substrates from fire or heat,and, also, for coating a wide variety of substrates to prevent flamepropagation.

Many solutions to the problem of fire-retardancy have heretofore beenproposed. Recognizing that drapes, curtains and decorations uponignition cause extreme heat for short durations but intense enough toignite adjacent painted surfaces and cause the spread of flame, methodsof treating these materials have been effective to some extent, but arenot in universal use. Proposed solutions for fire-retardant coatings andcompositions have embodied certain expedients to obtain fire retardancy;such as intumescence through the use of foam-producing materials,substitution of non-combustible materials, emission of non-flammablegas, and frequently a combination of all for maximum benefit. Whileseveral patents have been issued coven'ng various approaches to theproblem, public acceptance of the coatings contemplated thereby has beenlimited. It is believed that this is due in part to the failure of suchknown coatings to embody those properties which would make themserviceable. Thus, some of the known fire retarding coatings do not dryto a tack-free surface, or are so brittle as to chip on the surface towhich they are applied, or are so rough and coarse in texture as torequire recoating with conventional paints to obtain acceptableappearance, whereupon, much of the fire-retardant value is lost.

Among the further defects present in the existing fireretardant coatingsare: Deficient Water resistance or excessive sensitivity to water whichcauses water-spotting and/or efiervescence of materials on the surfaceof the coating thereby destroying the coatings decorative and protectivevalues and tending to decrease its fire retardance; difliculty inapplying the coating by means, such as by brush; excessively slow dryingof the coating; lack of uniform cell size and cell distribution in thecellular mat formed by the coating when the latter is exposed to fire orextreme heat, that the coating is inefficient as a heatinsulatingbarrier, which is one essential or prerequisite of effectivefire-retardance; lack of stability; and loss of fire and heat insulationupon aging or when film has been subject to heat.

An object of this invention is to provide a coating composition which isfree of the above mentioned defects of existing coatings.

Another object of this invention is to provide a coating compositionadapted to give fire-retardancy and latent heat insulation when appliedto combustible and noncombustible materials.

Another object of this invention is to provide a coating compositionwhich intumesces upon application of heat or flame.

A further object is to provide a composition to be applied, byconventional means, to unpainted and painted 3,637,95i Patented June 5,1962 surfaces, and that will produce, upon drying, a decorative andserviceable fire-retarding film of acceptable appearance. Applicationmay be made by brushing, roller coating, spraying, dipping, or any otherconventional method.

A further object is to provide fire-retarding coating compositions madeup of materials that are virtually insoluble in water and remain stableupon storage in suitable containers.

A further object of this invention is to provide a fireretardantcomposition which forms coatings having excellent resistance to checkingand cracking and also excellent resistance to washing and high humidityconditions without appreciable loss in fire-retardant properties.

A still further object of the present invention resides in the use ofcertain principles as well as materials for the binder as to givepractical solutions to fire-retardancy and normal coating properties.

The products of our invention may be applied as a surfacev coating toobjects or materials in general that are known as paintable surfaces.Combustible surfaces such as wood, cellulosic wallboard, plastic, paper,textiles, and non-combustible surfaces such as plaster, wallboard, andmetals are representative of such paintable surfaces on which thecoating will provide fire retarding and heat insulating properties.

While the compositions may be made inthe form of a solid, paste orliquid in accordance with this invention, the liquid compositionrepresents that which is normally used in painting practice.

Vast improvements in overcoming the defects described above and inachieving the above and related objects have been accomplished inaccordance with the invention by a unique combination of materials, bothorganic and inorganic. The essential components of our improvedfireretardant composition comprise, in combination, at least a waterinsoluble metal metaphosphate salt, and a water insoluble polyol, but itis preferred to also include a water insoluble aminoplast.

INSOLUBLE METAL METAPHOSPHATE Compounds such as ammonium phosphate,diammonium phosphate, phosphoric acid, ammonium sulfate, sulfamic acid,ammonium sulfamate, ammonium bromide, sodium tungstate, sodium borate,boric acid and urea phosphate have been utilized in variousfire-retardant compositions, but these materials have the disadvantageof leaching out or washing out because of their water solubility. Thismakes for a much reduced fire-retardancy when these compositions aresubjected to the action of water. The leaching or washing out of thespecified materials may also impair the aesthetic properties of surfaceson which these fire-retardant compositions are used because of thestreaks, water spots and deposits which are left on these surfaces bythe action of water or water vapor, such as steam, and such surfaces arealso less serviceable because washability is substantially reduced. Theuse of such compositions is prohibitive on surfaces Where there isconsiderable water or possible water condensation.

To overcome these faults we have used the water insoluble metalmetaphosphates. Examples of such salts are insoluble potassiummetaphosphate, insoluble sodium metaphosphate, zinc metaphosphate andcalcium metaphosphate. Other water insoluble metaphosphate salts areavailable and are applicable to this invention.

POLYOLS Water insoluble polyhydric compounds may be used in thecompositions of this invention. The polypentaerythritols are preferredin the compositions described herein. They may be employed in variouspolymeric forms, for example, as a dimer, trimer, etc. As specificexamples of polypentaerythritols may be mentioned di- AMINOPLASTS Theaminoplasts or amino aldehyde condensation products employed in thecompositions of this invention are Water insoluble and include a widevariety of materials which are prepared from aldehydes, organiccompounds containing at least one and preferably two amino groups havingat least two and preferably three replaceable hydrogen atoms. V p

The preferred aminoplasts for use in the compositions embodying thisinvention are the water insoluble ureaformaldehyde condensationproducts. '1" he molecular ratio of formaldehyde to urea may be between1 and 2.5 moles formaldehyde to 1 mole of'urea. Such condensationproducts are used as a dry solid. The use of the alkylatedmodificationsof such resins is likewise contemplated, particularly the butylatedmodifications of conventional area-formaldehyde and melamineformaldehyde resins. The butylated urea-formaldehydes are waterinsoluble and can be used as a solution without drying,

if necessary.

As examples of other aminoplasts which are useful ingredients in ourcompositions ofthis invention may be mentioned the condensation productsof an aldehyde with thionrea, guanidine, cyanamide, dicyandiamide andamino triazines having at least two amino groups as for example,melamine, 2-chloro-4,6 diamino-l,3,5 triazine, 2-hydroxy- 4-,6-diamino1,3,5 triazine alkyl guan'amines, aryl guanamines and the like. Ingeneral the useful aminoplasts are prepared by partially condensingformaldehyde with amino compounds containing from 1 to 9 carbon atomsand having a grouping with the following general formula? ing two freevalences which represents a double band Where N is a member selectedfrom the group consisting of a nitrogen atom having two single valencesattached to separate hydrogen atoms, a nitrogen atom having two singlevalences attached to separate carbon atoms, and a nitrogen atom havingtwo free valences which represent a double bond attached to a carbonatom; and where Y is a member selected from the group consisting of O,S, and a nitrogen atom having one free valence which is attached to acarbon or hydrogen atom. The

condensation products may be formed by using sufiicient formaldehyde toreact with from at least one to all of the replaceable hydrogen atoms oftheamino groups.

The aminoplasts may be prepared by using various aldehydcs'other thanformaldehyde. Examples of these other aldehydes are acetaldehyde,propionaldehyde, furfural, glyoxal and the like. However, formaldehydeand water soluble polymers of formaldehyde, such as para. formaldehyde,give superior aminoplasts for the purposes The coatings formed fromthese compositions possess the property of intumescing when exposed toan open flame or to heat and 'do not appreciably lose this property evenwhen the coating is washed with water periodically practicallynon-combustible.

Such residue is sufiiciently continuous and adherent to protect thesubstrate from combustion or the deleterious effects of heat andaccomplishes this result by preventing access of air to the substrateand at the same time insulating the substrate from is possible with acomposition containing only the meta-Z phosphate andpolypentaerythritols. The coating is highly resistant to leaching withWater. For example, a substrate coated with a composition according tothe invention was submerged for 30 minutes in water and then driedovernight at room temperature. This coated substrate was then exposed tothe direct flame of a Bunson Burner for 5 minutes, whereupon the coatingintumesced to form a puffed char of substantially the same volume as wasobtained with the same coating on a substrate that was not submerged inwater.

in addition to the'above mentioned essential components of compositionsaccording to our invention, the latter may also include suitablepigments to provide a range of colors and covering power necessary inproducing a suitable product, as well as inert pigment fillers, andadditional fire-retarding agents, such as chlorinated paraffins, waterinsoluble organic phosphates, and chlorinated biphenyls, such, as thearoclors and the like. i

' The compositions embodying the invention may also include a suitablevehicle, for example, a halogenated alkyd resin; thinners of the kindgenerally used in the coating industry to reduce the consistency of thecoating or to promote a general solvency of the system, for example,aliphatic'hydrocarbons such as mineral spirits, or aromatichydrocarbons, such as, xylol, toluol and the like, or mixtures thereof;and driers of the kind usually employed in the art to promote drying ofthe coating 01- to aid in promoting the film forming properties, suchas, salts of cobalt, manganese, lead, calcium and Zinc metals.

The halogenated alkyd resin vehicle is prepared in the conventional wayfrom halogenated dibasic acid, such as, tetrachlo-rophthalic anhydrlde,hexachloroendomethylenetetrahydro'phthalic acid and tetrabromophthalicanhydride; polyol, such as, glycerine and pentaerythritol; and anoxidizing oil, such as, soyabcan oil, linseed oil and dehydrated castoroil, or a mixture of oxidizing and nonoxidizing oils, such as, castoroil and cottonseed oil, or

'1 the fatty acids of such oils.

. The halogenated alkyd resin vehicle preferably contains 25 percentoil, by weight, but more or less oil may be included, although anincrease in the amount of oil decreases the intumescence of the coating.

A further understanding of the invention will'be obtained from thefollowing specific examples which'are intended to illustrate several ofthe most desirable compositions, but are not intended to limit the scopeof this 0 invention. It is to be noted that the parts and percentagesgiven in the examples are by weight, unless otherwise or exposed to highhumidity conditions over thenormal specified.

Example I a Parts Insoluble potassium metaphosphate 40 Dipentaerythritol-e 20 Aminoplast resin powder 15 Titanium dioxide 17 Antimony oxide 10Halogenated alkyd resin 30 Thinner 59 Cobalt drier 1 The aminoplastresin powder is prepared by reacting 1 mole of formaldehyde and 1 moleof urea.

The halogenated alkyd resin is prepared from dehydrated castor oil(representing 25% of total solids), glycerine andhexachloroendomethylenetetrahydrophthalic acid in accordance with thefollowing procedure:

The glycerine and castor oil are introduced into a reaction kettle andheated to 212 F., whereupon the acid is added. The temperature is thenraised slowly, in order to avoid foaming, to 370 F., at whichtemperature the oil, glycerine and acid are reacted in the presence ofcarbon dioxide to an acid number of 5 or less. The resulting alkyd resinis reduced with mineral spirits to a non-volatile of 56 percent.

The thinner consists of 80 percent mineral spirits (aliphatichydrocarbon solvent) and 20 percent aromatic solvent. The mineralspirits may be the product which is available under the name AmscoMineral Spirits from the American Mineral Spirits Company, while thearomatic solvent may be the product of the same company sold under thename Amsco G.

The drier is cob-alt naphthenate having a metal content of 6 percent.

The paint is prepared in conventional paint malc'ng equipment. Theingredients are mixed in a paste mixer or other suitable equipment toproduce a paste consistency. When a smooth resulting coating is desired,the resultant paste from the paste mixer or other equipment may beground on a roller mill, a ball mill, high speed stone mill, or othertypes of mills.

The above paint is applied by conventional means to an unpainted orpainted surface, and, upon drying produces a decorative and serviceablefilm of acceptable appearance.

This paint is comparable in stability to commercial paints.

Example II Parts Insoluble sodium metaphosphate 40 Tripentaerythritol 20Titanium dioxide Antimony oxide 20 Halogenated alkyd resin 30 Thinner 47Cobalt drier 1 Lead drier 2 The halogenated alkyd resin, thinner andcobalt drier in the above Example II are the same as those described inconnection with Example I, while the lead drier is lead naphthenatehaving a metal content of 24 percent.

Example III Parts Calcium metaphosphate 40 Dipentaerythr-itol 20Aminoplast 20 Titanium dioxide Antimony oxide 15 Halogenated alkyd resin30 Thinner 53 Manganese drier 2 The aminoplast is prepared by reacting 2moles of formaldehyde with 1 mole of urea.

The halogenated alkyd resin and thinner of Example III are the same asdescribed in connection with Example I, while the manganese drier ismanganese naphthenate having a metal content of 6 percent.

The aminoplast is prepared by reacting 1 mole of formaldehyde and 1 moleof urea.

. 6 The halogenated alkyd resin thinner and cobalt drier of Example IVare the same as described in connection withExample I.

Example V Parts Insoluble sodium metaphosphate 40 TripentaerythritolArninoplast 20 Titanium dinxide Halogenated alkyd resin Thinner 47Cobalt drier 1 Lead drier 2 The aminoplast is prepared by reacting 1mole of formaldehyde and 1 mole of urea.

The halogenated alkyd resin, thinner and cobalt drier of Example V arethe same as described in connection with Example I, while the lead drieris the same as that in Example 11.

20 Example VI Parts Insoluble sodium metaphosphate 40 Tripentaerythritol20 25 Aminoplast 20 Halogenated alkyd resin 30 Thinner 47 Cobalt drier 1Lead drier 2 The aminoplast is prepared by reacting 1 mole offormaldehyde and 1 mole of urea.

The halogenated alkyd resin, thinner and driers of the above Example VIare the same as described in Example II.

Example VII Parts Insoluble sodium metaphosphate 4 Tripentaerythritol 20Aminoplast 20 Antimony oxide 17.5 Titanium dioxide 75 Halogenated alkydresin 25 Thinner 40 Manganese drier 1 Lead drier 1.5

The aminoplast is prepared by reacting 2 moles of formaldehyde and 1mole of urea.

The halogenated alkyd resin and thinner of Example VII are the same asdescribed in Example I, while the lead drier is the same as described inExample 11 and the manganese drier is the same as in Example III.

The amount of insoluble metaphosphate can be reduced as above and stillobtain intumescenoe. The intumescence is not as full or as much as inthe other examples.

Example VIII and 1 mole of formaldehyde.

The aqueous dispersion of halogenated alkyd resin is prepared bycombining the following materials in the order given. Vigorousmechanical stirring should attend the incorporation of each component.

spanner V 7 a 'Parts Halogenated alkyd resin; 272 Cobalt drier--- s H 1Iso octyl phenyl poly ethoxyethanol 6 Sulfon-ated alkyl ester 1.5 Aquaammonia (28% NH 1 I 1.5% aqueous soiution'of methyl cellulose, 4000 cps-1.6 Water" a a a 34 The hal ogenated alkyd resin and the cobalt drierare 'the same as described in connection with Example I.

The aminoplast resin is prepared from 1 mole of urea and 1 mole offormaldehyde.

The halogenated alkyd resin, thinner and cobalt drier are the same asdescribed in' connection with Example I, while the manganese drier isthe same as in Example III.

Iso-octyl phenyl- Sulfonated alkyl ester is obtainable as" Example X a aParts Insoluble sodium metaphosphate 40 Tripentaerythritol .1.- 20'Aminoplast a 7 20 Barytes (barium sulfate pigment) a 20 Titanium di0xidea a= s 10 Halogenated alkyd resin' -1 28 Thinner I 1 52 Cobalt drier .5Manganese drier .5

The aminoplast is prepared from 1 mole of urea and 1 mole offormaldehyde.

The halogenated alkyd resin, thinner and driers are the same asdescribed in connection with Example IX.

While we have described several specifilc embodiments of our invention,it is to be understood that we do not Wish to be limited thereto, asobviously various changes and modifications may be made therein withoutdeparting from the spirit and scope of the invention as defined in theappended claims. a

What is claimed is: V I V 1. An intumescing, water resistant,fire-retardant composition comprising at least one water-insoluble metalmetaphosphate selected from the group consisting of zinc metaphosphate,calcium metaphosphate, insoluble sodium metaphosphate, insolublepotassium metaphosphate and insoluble. potassium polymetaphosphate; apolypentaerythritol present in an amount between 10% and 200%, byweight, of said metal metaphosphate and being selected from the groupconsisting of dipentae'rythritol, tripentaerythritol and mixturesthereof; and a water insoluble aminoplast resin which is thecondensation prod not of an aldehyde and an: amino compound containingfrom 1 to 9 carbon atoms and having the grouping where N is a memberselected from the groupconsisting of a nitrogen atom having two singlevalences attached to separate atoms selected from the" group consistingof hydrogen and "carbon atoms, and a nitrogen atom having two freevalences representing a double bond attached to a carbon atom; and whereY is a member selected firom the group consisting of O, 'S, and anitrogen atom with one free valence'which is attached to an atomselected from the group consisting of hydrogen and carbon atoms; theweight of metal metaphosphatei u said composition being between 25% and200% of the combinedweight of said polypentaerythritol and saidaminoplastresin.

2. An intumescin'g, water-resistant, fire-retardant composition as inclaim 1; wherein said aminoplast resin is 1 selected from the groupconsisting of urea-formaldehyde and urea-paraformaldehyde condensationproducts, the butylated modifications of urea-formaldehyde andmelamine-formaldehyde resins, and the condensation products of aldehydeswith thiourea, guanidine, cyanamide,

dicyandiamide and amino triazzines having at least two amino groups. s

3. A substrate coated on at' least one surface thereof with a. waterresistant, intumescing fire-retardant coating comprising at least onewater-insoluble metal metaphosphate selected from the group consistingof zinc metaphosphate, calcium metaphosphate, insoluble sodiummetaphosphate, insoluble potassium metaphosphate and insoluble potassiumpolymetaphosphate; a polypentaerythritol present in an amount between10% and 200%, by Weight, of said metal metaphosphate, and being selectedfrom the group consisting of dipentaerythritol, tri pentaerythritol andmixtures thereof; a' water insoluble aminoplast resin which is thecondensation product of an aldehyde and an amino compound containingfrom 1 to 9 carbon atoms and having the grouping where =N is a memberselected from the group consisting of a nitrogen atom having two singlevalences attached to separate atoms selectedfrom the group consisting ofhydrogen and carbon atoms, and a nitrogen atom having two free valencesrepresenting a double bond attached to a carbon atom; and Where Y is amember selected from the group consisting of O, S, and a a nitrogen atomwith one free valence which is attached to an atom selected from thegroup consisting of hydrogen and carbon atoms; the weight of metalmetaphosphate in said composition being between 25% and 200% of thecombined, weight of said polypentaerythritol and I said aminoplastresin; and a binder.

4. A coated substrate as in claim 3; wherein said aminoplast resin isselected" from the group consisting of urea-formaldehyde andurea-paraformaldehyde condensation' products," the butylatedmodifications of ureaformaldehyde and melamine-formaldehyde resins, andthe condensation products of aldehydes with thiourea, guanidine;cyanamide, dicyandiamide and amino triazines having at :least twoaminogroups.

5. A coated substrate as in claim 4; wherein said binder is ahalogenated alkyd resin which is the reaction product of a halogenateddibasic acid selected from the group consisting of tetrachlorophthalicanhydn'de, tetrabromophthalic anhydride andhexachloroendomethylenetetrahydrophthalic' acid, a polyol selected fromthe group consisting of glycerine' and polypentaerythritol, and amaximum of'25%', by weight; of vegetable oil.

6. An intumescingwater resistant, fire-retardant compositionrcmprisingat least one water-insoluble metal metaphosphate selected from the groupconsisting of zinc m'etaphosphate, calcium metaphosphate; insolublesodium metaphosphate, insoluble potassium metaphosphate and insolublepotassium polymetaphosphate, and'a polypen- 75 taerythritol selectedfrom the group consisting of dipen-v taerythritol, tripentaerythritoland mixtures thereof, said polypentaerythritol being present in anamount between 38% and 200%, by weight, of said metal metaphosphate.

7. An intumescing, water resistant, fire-retardant composition as inclaim 6; further comprising a halogenated alkyd resin which is thereaction product of a halogenated dibasic acid selected from the groupconsisting of tetrachlorophthalic anhydride, tetrabromophthalicanhydride and hexachloroendomethylenetetrahydrophthalic acid, a polyolselected from the group consisting of glycerine and polypentaerythritol,and a maximum of 25%, by weight, of vegetable oil.

8. An intumescing, water resistant, fire-retardant composition as inclaim 7; wherein said halogenated alkyd resin is present as an aqueousdispersion thereof.

9. An intumescing, fire-retardant composition as in claim 6; furthercomprising urea-formaldehyde resin, the weight of said metalmetaphosphate being between 25% and 200% of the combined weight of saidpolypentaerythritol and said urea-formaldehyde resin.

10. A substrate coated on at least one surface thereof With a waterresistant, intumescing fire-retardant coating comprising at least onewater-insoluble metal metapho sphate selected from the group consistingof zinc metaphos'phate, calcium metaphosphate, insoluble sodiummetaphosphate, insoluble potassium metaphosphate and insoluble potassiumpolymetaphosphate, a polypentaerythritol present in an amount between38% and 200%, by weight, of said metal metaphosphate and being selectedfrom the group consisting of dipentaerythritol, tripentaerythritol andmixtures thereof, and a binder formed by a halogenated alkyd resin whichis the reaction product of a halogenated dibasic acid selected from thegroup consisting of tetrachlorophthalic anhydride, tetrabromophthalicanhydride and hexachloroendomethylenetetrahydrophthalic acid, a polyolselected from the group consisting of glycerine and polypentaerythritol,and a maximum of 25 by Weight, of vegetable oil.

11. A coated substrate as in claim 10; wherein said binder is an aqueousdispersion of said halogenated alkyd resin.

References Cited in the file of this patent UNITED STATES PATENTS2,853,471 Beadell Sept. 23, 1958 2,877,204 Duhnkrack et al. Mar. 10,1959 2,881,145 Schmutzler Apr. 7, 1959 2,912,393 Stilbert et a1 Nov. 10,1959 2,916,467 Williams et al. Dec. 8, 1959 2,941,894 McAdoW June 21,1960

1. AN INTUMESCING, WATER RESISTANT, FIRE-RETADANT COMPOSITION COMPRISINGAT LEAST ONE WATER-INSOLUBLE METAL METAPHOSPHATE SELECTED FROM THE GROUPCONSISTING OF ZINC METAPHOSPHATE, CALCIUM METAPHOSPHATE, INSOLUBLESODIUM METAPHOSPHATE, INSOLUBLE POTASSIUM METAPHOSPHATE AND INSOLUBLEPOTASSIUM POLYMETAPHOSPHATE; A POLYPENTAERYTHRITOL PRESENT IN AN AMOUNTBETWEEN 10% AND 200%, BY WEIGHT OF SAID METAL METAPHOSPHATE AND BEINGSELECTED FROM THE GROUP CONSISTING OF DIPEMTACRYTHRIOTOL,TRIPENTACRYTHRITOL AND MIXTURES THEREOF; AND A WATER INSOLUBLEAMINOPLAST RESIN WHICH IS THE CONDENSATION PRODUCT OF AN ALDEHYDE AND ANAMINO COMPOUND CONTAINING FROM 1 TO 9 CARBON ATOMS AND HAVING THEGROUPING